On Sun, 17 Feb 2013, Ronald wrote:
> Current head gives this when I plug a 'Mass Storage Device' into a 2.0 hub:
>
> [ 842.760400] hub 1-0:1.0: unable to enumerate USB device on port 3
> [ 843.080058] usb 1-3: new high-speed USB device number 48 using ehci-pci
> [ 858.230072] usb 1-3: device descriptor read/64, error -110
> [ 873.490070] usb 1-3: device descriptor read/64, error -110
>
> Reverting the following commit makes it work again:
>
> commit 55bcdce8a8228223ec4d17d8ded8134ed265d2c5
> Author: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Date: Fri Jan 25 16:52:45 2013 -0500
>
> USB: EHCI: remove ASS/PSS polling timeout
>
> This patch (as1647) attempts to work around a problem that seems to
> affect some nVidia EHCI controllers. They sometimes take a very long
> time to turn off their async or periodic schedules. I don't know if
> this is a result of other problems, but in any case it seems wise not
> to depend on schedule enables or disables taking effect in any
> specific length of time.
>
> The patch removes the existing 20-ms timeout for enabling and
> disabling the schedules. The driver will now continue to poll the
> schedule state at 1-ms intervals until the controller finally decides
> to obey the most recent command issued by the driver. Just in case
> this hides a problem, a debugging message will be logged if the
> controller takes longer than 20 polls.
>
> I don't know if this will actually fix anything, but it can't hurt.
On Thu, 14 Feb 2013, Paul Hartman wrote:
> I ran git bisect on kernel and found this commit. "but it can't hurt"
> famous last words :)
>
> 269ef9f3805a5ec17ddf3dd5f13d5e09598c155b is the first bad commit
> commit 269ef9f3805a5ec17ddf3dd5f13d5e09598c155b
> Author: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
> Date: Fri Jan 25 16:52:45 2013 -0500
>
> USB: EHCI: remove ASS/PSS polling timeout
Okay. I have no idea what could be going wrong, but obviously we need
to find out. The patch below will add a bunch of debugging info
related to this commit. For it to work, you will need to enable
CONFIG_USB_DEBUG when you build your kernels.
Please post the output from "dmesg", showing what happens starting from
boot-up until a device fails.
Alan Stern
Index: usb-3.8/drivers/usb/host/ehci-hcd.c
===================================================================
--- usb-3.8.orig/drivers/usb/host/ehci-hcd.c
+++ usb-3.8/drivers/usb/host/ehci-hcd.c
@@ -287,6 +287,9 @@ static void ehci_quiesce (struct ehci_hc
/* wait for any schedule enables/disables to take effect */
temp = (ehci->command << 10) & (STS_ASS | STS_PSS);
handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, temp, 16 * 125);
+ ehci_dbg(ehci, "quiesce: temp %x status %x\n", temp,
+ ehci_readl(ehci, &ehci->regs->status) &
+ (STS_ASS | STS_PSS));
/* then disable anything that's still active */
spin_lock_irq(&ehci->lock);
@@ -296,6 +299,9 @@ static void ehci_quiesce (struct ehci_hc
/* hardware can take 16 microframes to turn off ... */
handshake(ehci, &ehci->regs->status, STS_ASS | STS_PSS, 0, 16 * 125);
+ ehci_dbg(ehci, "quiesce2: status %x\n",
+ ehci_readl(ehci, &ehci->regs->status) &
+ (STS_ASS | STS_PSS));
}
/*-------------------------------------------------------------------------*/
Index: usb-3.8/drivers/usb/host/ehci-timer.c
===================================================================
--- usb-3.8.orig/drivers/usb/host/ehci-timer.c
+++ usb-3.8/drivers/usb/host/ehci-timer.c
@@ -110,6 +110,8 @@ static void ehci_poll_ASS(struct ehci_hc
want = (ehci->command & CMD_ASE) ? STS_ASS : 0;
actual = ehci_readl(ehci, &ehci->regs->status) & STS_ASS;
+ ehci_dbg(ehci, "ASS want %x actual %x count %d\n",
+ want, actual, ehci->ASS_poll_count);
if (want != actual) {
@@ -126,8 +128,10 @@ static void ehci_poll_ASS(struct ehci_hc
/* The status is up-to-date; restart or stop the schedule as needed */
if (want == 0) { /* Stopped */
- if (ehci->async_count > 0)
+ if (ehci->async_count > 0) {
+ ehci_dbg(ehci, "Set ASE\n");
ehci_set_command_bit(ehci, CMD_ASE);
+ }
} else { /* Running */
if (ehci->async_count == 0) {
@@ -142,6 +146,7 @@ static void ehci_poll_ASS(struct ehci_hc
/* Turn off the async schedule after a brief delay */
static void ehci_disable_ASE(struct ehci_hcd *ehci)
{
+ ehci_dbg(ehci, "Clear ASE");
ehci_clear_command_bit(ehci, CMD_ASE);
}
@@ -157,6 +162,8 @@ static void ehci_poll_PSS(struct ehci_hc
want = (ehci->command & CMD_PSE) ? STS_PSS : 0;
actual = ehci_readl(ehci, &ehci->regs->status) & STS_PSS;
+ ehci_dbg(ehci, "PSS want %x actual %x count %d\n",
+ want, actual, ehci->PSS_poll_count);
if (want != actual) {
@@ -172,8 +179,10 @@ static void ehci_poll_PSS(struct ehci_hc
/* The status is up-to-date; restart or stop the schedule as needed */
if (want == 0) { /* Stopped */
- if (ehci->periodic_count > 0)
+ if (ehci->periodic_count > 0) {
+ ehci_dbg(ehci, "Set PSE\n");
ehci_set_command_bit(ehci, CMD_PSE);
+ }
} else { /* Running */
if (ehci->periodic_count == 0) {
@@ -188,6 +197,7 @@ static void ehci_poll_PSS(struct ehci_hc
/* Turn off the periodic schedule after a brief delay */
static void ehci_disable_PSE(struct ehci_hcd *ehci)
{
+ ehci_dbg(ehci, "Clear PSE");
ehci_clear_command_bit(ehci, CMD_PSE);
}
--
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